Accession Number : ADA186841

Title :   Numerical Investigation of Orographically Enhanced Instability.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Byrne, Gerald T

PDF Url : ADA186841

Report Date : Sep 1987

Pagination or Media Count : 60

Abstract : The NEPRF spectral baroclinic primitive equation model with six layers was numerically integrated over time to examine the effects that vertical wind profiles have on the development of lee cyclogenesis. In addition, the model was run in both linear and nonlinear modes to isolate their effects on the tests. The objective was to simulate a cold front moving over a high mountain ridge, similar to the Alps or Rockies, by implementing a wind reversal profile and to determine if this was conductive to lee cyclogenesis. It was found that the wind reversal profile produced favorable cyclonic growth, particularly when the model was in a linear mode. A nonlinear wind reversal test also produced positive results but only for a relatively short time; thereafter nonlinear interactions dampened cyclonic growth considerably. In addition, two tests were run that allowed the mountain to grow in a very short time to isolate inertial gravity wave interactions. The gravity waves did produce considerable oscillations in the two tests, but after 15 hours or so these two tests showed similar cyclonic growth to the previous tests. (Theses)

Descriptors :   *COLD FRONTS, *CYCLONES, *MOUNTAINS, *WIND, *ATMOSPHERE MODELS, *WEATHER FORECASTING, ATMOSPHERIC MOTION, EQUATIONS, GRAVITY WAVES, GROWTH(GENERAL), INERTIAL SYSTEMS, INTERACTIONS, MATHEMATICAL MODELS, NONLINEAR SYSTEMS, NUMERICAL ANALYSIS, OSCILLATION, PROFILES, REVERSIBLE, RIDGES, THESES, VERTICAL ORIENTATION, CIRCULATION, LAYERS, NUMERICAL INTEGRATION, SPECTRUM ANALYSIS, LINEAR SYSTEMS, DAMPING, DIGITAL SIMULATION, MATHEMATICAL PREDICTION

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE